A noncontact communication medium includes a processing circuit mounted on a substrate having a coil to induce power by action of an external magnetic field applied from an outside, and processing circuit having an internal capacitor; and an external capacitor externally attached to the processing circuit. The external capacitor, the internal capacitor, and the coil constitute a resonance circuit resonating at a predetermined resonance frequency by the action of the external magnetic field. The external capacitor is connected in parallel with the internal capacitor, and the resonance circuit has a Q-value determined in accordance with a characteristic of the external capacitor.

This disclosure describes techniques for operating an inductive coupling reader. The techniques include operations comprising: detecting a change in a resonance frequency of the inductive coupling reader; comparing the change in the resonance frequency to a threshold; determining that the change in the resonance frequency falls outside the threshold; and activating a compensation circuit to offset the change in the resonance frequency of the inductive coupling reader in response to determining that the change in the resonance frequency falls outside the threshold.

A wearable device, such as a finger ring worn by a user, communicates information about a user to a reader that uses the information in order to perform a transaction. Such wearable device may be conveniently carried by and accessible to the user such that utilization of the device for the transaction is less burdensome for the user, thereby encouraging use of the device for particular transactions. Indeed, in some cases, such as when the device is implemented as a finger ring or other type of jewelry, the user may be encouraged to carry the device in an exposed manner such that it is readily available for the transaction without the user having to search in a wallet, pocket, or purse for the device.

A mobile device includes a smartcard controller that does not rely on power received from an interrogating RF field. The mobile device also includes a small inductive device capable of inductive coupling with an RFID reader. The smartcard controller includes circuitry to modulate an impedance of a port coupled to the inductive element when in the presence of an interrogating RF field at substantially 13.56 MHz.

A transponder for a RFID-type wireless communication and contactless identification system configured to be affixed to (or close to) structure intended to be buried, said transponder comprising: a set of antenna segments consisting of electrical wires constituting at least a first and a second antenna element (203-1, 203-2), a circuit board comprising a RFID chip and at least one tuning capacitance (202x) as well as coupling means (281) allowing the electrical coupling of said antenna segments;
characterized in that said antenna segments are arranged close to each other, at a distance of less than 3 mm and preferably less than 1 mm, so as to allow the appearance of coupling capacities (280) capable of widening the band of tolerance on the RFID resonance frequency.

In accordance with a first aspect of the present disclosure, a radio frequency identification (RFID) transponder is provided, comprising a modulator and a controller, wherein: the modulator is configured to generate a modulated signal to be transmitted to an external RFID reader; the controller is configured to increase a transmitter impedance during a first period of time; the controller is configured to decrease the transmitter impedance by enabling the modulator during a second period of time. In accordance with a second aspect of the present disclosure, a corresponding method of operating a radio frequency identification (RFID) transponder is conceived.

This disclosure describes techniques for operating an inductive coupling reader. The techniques include operations comprising: detecting a change in a resonance frequency of the inductive coupling reader; comparing the change in the resonance frequency to a threshold; determining that the change in the resonance frequency falls outside the threshold; and activating a compensation circuit to offset the change in the resonance frequency of the inductive coupling reader in response to determining that the change in the resonance frequency falls outside the threshold.

Embodiments of the present disclosure generally relate to a wireless identification tag configured to harvest ambient energy and transmit an identification signal intermittently, and system and methods for use thereof. In one implementation, the tag may include an antenna configured to receive ambient energy. The tag may also include an energy storage component configured to aggregate and store the received ambient energy. The tag may also include a transmitter electrically connected to the energy storage component and configured to transmit the identification signal. The tag may also include a circuit connected to the transmitter and configured to implement an identification transmission rule, to cause the transmitter to delay sending the identification signal even when sufficient energy for transmission of the identification signal is aggregated and stored in the energy storage component.

Embodiments of the present disclosure generally relate to systems and methods for providing privacy to downstream owners of electronically tagged goods. In one implementation, the system may include at least one processor that may be configured to store IDs for a plurality of tags including at least a first owner ID and a second owner ID for a particular tag; associate first information of the particular tag with the first owner ID at a time when the first owner of the particular tag is recorded as owning the tag; record a transaction transferring ownership of the particular tag from the first owner to a second owner; and after the transfer of ownership, associate second information of the particular tag with the second owner ID, and prevent the second owner from accessing the first information.

RFID-enabled composite metal transaction cards may include a security layer comprising a hologram or diffraction grating on a metal layer having a slit. The metal layer may reside on a front or rear face, or as a core layer in the construction of the card. The security layer, with or without a carrier layer, may be hot stamped to the metal layer with a protective hard coating, to camouflage the existence of a discontinuity in the metal layer. The metal layer with slit or slits may be coated with a baked-on-ink to provide color and to partially fill the slit or slits. A metal foil, holofoil or a holographic metal film may be provided with a discontinuity in the form of a slit and may be a decorative foil mounted to a card body containing a metal layer with a slit.